On the eve of Earth Day, the PBS Frontline documentary "Poisoned Waters" put a national spotlight on Puget Sound's health problems, highlighting stormwater as the number one threat facing Puget Sound and other waterways around the country.

Washington Department of Ecology (Ecology) studies support Frontline's conclusion. Josh Baldi, Ecology's special assistant for Puget Sound, said Ecology is actively cleaning up many near-shore areas that have high levels of toxic chemicals in sediments.

"It's clear these efforts are critical to restoring the health of near-shore environments in Puget Sound," he said. "Our greatest challenge, however, is getting everyone who lives around the Sound to help reduce the constant stream of toxics entering the Sound every day."

Baldi added that Ecology inspectors, local source control inspectors, industrial environmental coordinators and other "boots on the ground" face continued hard work to control and prevent sources of toxic chemicals.

Establishing good management practices, such as low-impact development and use of porous materials for hard surfaces where possible, will help reduce the load of toxic chemicals coming from stormwater.

To help focus its efforts, Ecology has developed a new computer prediction tool that analyzes how toxic chemicals move through Puget Sound's water, sediment, and marine life. The tool will boost the state's understanding of how stormwater pollution affects conditions of Puget Sound.

For starters, the tool tells scientists that stormwater is still carrying PCBs (polychlorinated biphenyls) into Puget Sound, even though the family of chemicals was banned 30 years ago. PCBs are widely distributed throughout the regional landscape. For decades, they were commonly used in adhesives, asphalt roofing materials, paint, lubricants, caulking and grout, and coolant for hot electrical equipment.

When PCBs were banned in 1979, the action dramatically decreased sources of the chemical in the region. While no longer manufactured, PCBs are still in limited use, and toxic chemicals with similar properties are in use throughout the region.

The Ecology computer model simulates water circulation, transport of toxic chemicals in water and sediments, and the build-up of toxics (bioaccumulation) in the Puget Sound food web.

Ecology used PCBs as a test case for the model because relative to other toxic contaminants, there was a great deal of existing information on concentrations in different parts of the Sound.

"PCBs are probably a good indicator of how other toxic chemicals with similar properties such as banned flame retardants, chlorinated pesticides and mercury are getting into and moving through the Puget Sound ecosystem," said Puget Sound Partnership Executive Director David Dicks.

Ecology scientists will use this model to look at other toxic contaminants in Puget Sound, such as zinc, copper, lead and petroleum products.

"This new science and the advances of the last several years show us how enormous and complex the stormwater problem is, and that we are going to need a lot of help to fix it," said Baldi. "Orca whales, salmon, herring and rockfish accumulate and carry PCBs in their bodies. The toxic pollutants make our resident orcas more vulnerable to infectious disease, impair reproduction, and impede normal growth and development."

Although PCBs are found in greater concentrations in urban areas -- especially where significant spills have occurred -- forested lands also are contaminated due to air deposition.

Today, a key source of PCBs is accumulated deposits from air pollution. Erosion of disturbed soil, often due to land use changes like development, releases these accumulated deposits onto hard surfaces, such as roads, into stormwater and into Puget Sound.

"Traditional methods of developing land are one of the main reasons PCBs and similar toxic chemicals today are being washed into Puget Sound," said Rob Duff, manager of Ecology's environmental assessment program. "Our modeling tool predicts that if we can decrease the toxics in surface runoff now, we can decrease concentrations of toxics in our sediments, fish and other marine life in Puget Sound."

Ecology and many others are collecting new information to improve the overall understanding about where toxic chemicals exist -- and how they can be prevented from getting into the food web.

"The model predicts that more than 95 percent of the PCBs already in the aquatic ecosystem are present in sediments and from there begin to bioaccumulate in various aquatic species," Dicks said. "We need to zero in on the sources of contamination as well as continue targeted cleanup efforts in our urban bays throughout the region."

The new computer model will be useful in evaluating how Puget Sound's health responds to various levels of reductions in inputs of toxic chemicals.

Business, environmental, and local government interests are helping the state with its fight against pollution. At their request, the Legislature recently passed a bill to establish a stormwater technology resource center. This center would provide for an on-going partnership among the state, local governments and private parties to find practical solutions to stormwater challenges. This includes research, development, technology demonstration, technology transfer, education, outreach, recognition, and training programs.

Ecology and the Partnership also are working to identify and reduce the key sources of toxic pollutants that feed stormwater and other pathways. Focusing efforts on the major pathways and sources of toxic chemicals entering the Puget Sound environment will benefit fish, shellfish and other freshwater and marine life while reducing exposure to everyone who eats them.

As noted in the documentary, effective restoration takes local action by committed citizens. Restoration can improve the quality of life as well as protect the Sound.